DNA Degradation

To utilize the catechol-2,3-dioxygenase, encoded by the xylE gene, and any other proteins we plan incorporate into our system, there are two approaches that can be taken to move it out of the lab setting and into the real world. The first approach is to compartmentalize the protein allowing for it to be isolated from the cell and applied independent of the organism. This method is addressed by using the lumazine synthase microcompartment. The second approach is to keep our organism separated from the environment. To do so, we can bring the tailings water to the cells at a place that would be similar to a refining or water treatment plant to prevent their spreading.

In 2007, UC Berkeley submitted a BioBrick containing an inducible BamHI gene. When expressed, this gene will produce the restriction endonuclease. This enzyme will then "chew up" the genomic material of the cell. The 2007 UC Berkeley team characterized the gene and demonstrated that when it is expressed does not affect the function of already translated protein. They did this by showing that red florescent protein (RFP) remains functional after the expression of this “suicide gene”. When a bacterial cell replicates, it must first replicate its genome. If we express the “suicide gene” it will essentially render the cell into a sack of functioning proteins. By degrading the DNA of the organism, we reduce the risk of genetic propagation since there is no template to replicate from. A public concern regarding applying a genetically engineered system into the real world is the risk it may have of escaping into the environment. A treatment plant would act as a mediator between the organism and the environment. Of course aseptic techniques would be followed. The “suicide gene” can be used as an additional safety precaution. If an organism somehow found its way into the environment (however unlikely this may be), it would not be able to propagate since it lacks DNA. Therefore, this would allow for better regulation of the microorganism.